Super Mario 3D World is a 3D platformer action game for the Wii U. It was released on November 21, 2013 in Japan, November 22, 2013 in North America, November 29, 2013 in Europe, and November 30, 2013 in Australia. Super Mario 3D World is the fifteenth title in the Super Mario series, the sixth original 3D Mario title, the seventh 3D Mario title overall, and the fifth 3D Mario title on a home console after Super Mario Galaxy 2. The title indirectly follows the Nintendo 3DS game Super Mario 3D Land.

The game plays very similarly to Super Mario 3D Land, being a 3D platformer though with gameplay similar to the 2D games. This game retains its predecessor's similarity to Super Mario Bros. 3 (with colorful blocks, the Super Leaf, Spikes and the Lose a Life theme returning from that game); many elements from Super Mario World are returning as well, such as Chargin' Chucks and Kuribons, now with an official English name, Galoombas. Stages are once again open yet linear, have a time limit, and end by grabbing the classic Goal Pole at the end. Green Stars return from the Super Mario Galaxy games, taking the role of the Star Medals from Super Mario 3D Land. There are also various stamps that the player can find. There is one in each level and they can be used in Miiverse posts. The game also seems to be slightly more puzzle-focused than its predecessors. The path from the start of the level to the goal is no longer a straight shot, and the players would often have to use certain power-ups and items in order to find the way ahead. Additionally, the game also features a score system, the first time one has appeared in a 3D Mario game.

Power-ups, like the Fire Flower and Super Leaf, make a return, along with almost every item from Super Mario 3D Land (excluding the Statue Leaf and P-Wing). The Mega Mushroom from New Super Mario Bros. also make an appearance. There are also several new power-ups and suits; The most prominent of the new power-ups is the Super Bell, a power-up that grants the player a Cat Suit, allowing them to lunge at and claw enemies and climb up walls.

For the first time in a 3D Super Mario title the game supports up to four player simultaneous multiplayer, allowing players to control Mario, Luigi, Princess Peach, Toad and Rosalina; additional players can drop in at any time by pressing Classic Controller a Button/Two Button, and can drop out by pausing and pressing Minus Button on the pause menu, similar to New Super Mario Bros. Wii and New Super Mario Bros. U; in this game, however, players can also switch characters before entering a stage. Each character has different abilities, much like they had in Super Mario Bros. 2. The multiplayer works similarly to New Super Mario Bros. Wii and New Super Mario Bros. U, in that players can enter a bubble at any time, pick each other up and throw each other, bounce on each others' heads, and so on. Players also share lives when playing in multiplayer, rather than each player having a separate life counter. The game uses a cooperative and competitive multiplayer system; each player works together to get to the end of the stage, but is ranked based on points earned out of the total score at the end. The player that scores the most points for one stage receives a crown, which can be stolen by the other players and gives the player wearing it at the end of the stage a score bonus.

In addition to being the default player one controller, the GamePad can be used at any point during gameplay to interact with the environment, allowing players to stun enemies, momentarily reveal hidden objects (both in levels and on the map), hit blocks, stop moving platforms, and various other functions, similar to the Co-Star Luma from Super Mario Galaxy 2.0' and Boost Mode from New Super Mario Bros. U. The GamePad can also be used to control the camera during gameplay by pressing the button on the bottom corner of the GamePad screen and tilting the controller, in what is known as Free Camera Mode. It works in a similar fashion to the camera from Super Mario 64 and Super Mario Sunshine. The GamePad can also be used for Off-TV Play at any point.

Super Mario 3D World features Nintendo Network support in the form of Miiverse integration and Ghost Miis, which is first enabled on a given save file after progressing a bit into the game. With Miiverse, players can make a post at any point on the World Map or after completing a stage by tapping the "Post" icon; other players' posts can also be viewed on the World Map by walking up to their Miis and pressing Classic Controller a Button/Two Button, or on the top of the stage results screen. Ghost Miis are created after the player clears a course without losing a life, which creates a ghost that perfectly recreates their movements throughout the course, and is automatically distributed to other players. Players who receive the data can play through an already cleared course with three Ghost Mii characters. While traveling through a course, the Ghost Mii characters occasionally carry gifts behind them that when caught can contain various items. The Nintendo Network settings for this title can be changed at any point by pausing the game and selecting the Nintendo Network icon button.

As part of the Year of Luigi celebration, also included is another game that can be accessed from the title screen after beating the main game once (or immediately if New Super Luigi U save data is present).[8] The game, titled Luigi Bros., has gameplay similar to that of Mario Bros., but with Luigi as the only playable character. The game can be accessed by touching the Luigi button found in the bottom-left corner of the screen. Also, similar to New Super Luigi U, multiple 8-bit Luigi sprites can be found throughout the game.

Throughout the playthrough, Arin plays as Peach, and Danny plays as Luigi, before switching to Toad later on, until they mix it up in Goomba Ninjas. Later, Arin plays as Rosalina after unlocking her in Running Ahead.

In the beginning, the grumps didn't seem overly concerned with getting every green star and stamp in the game, and usually skip over them if they can't find them easily. However, they still make contests over trying to get more collectables per level and keeping the crown. In some cases, Danny would try to rush through a level and/or attack Arin just to get that crown (and sometimes vice versa).

Often at times, during the showing of Miiverse posts after beating a level, the grumps would check out the comments sliding on the screen. Some of them they would agree, others they would laugh about, and at times some Mii's show their support for the grumps in which they would like and/or reply back (however, they do miss a few). However, after beating Meowser and the grumps' plan to renovate the grump room, their wifi is turned off and the Miiverse is turned off.

After beating Meowser and assuming the game is over, the grumps find out that there are secret worlds and some levels require a large amount of green stars. So the grumps would go back to previous worlds to collect any green stars they missed.

After beating the final level of World Flower, Arin and Danny stated that they would continue the series through live streams, after 59 episodes. It is unknown if after they collect all of the green stars, golden flagpoles and stamps, that they would do the final levels of the game, or upload their live streams as if they were regular episodes.

This playthrough features several lives lost during their gameplay on Game Grumps, easily clocking well into the hundreds, counting both those lost by Danny and Arin. Notably, Danny dies much more frequently than Arin. It is only surpassed by VVVVVV on Steam Trainand possibly later Super Mario Maker.

Occasionally, Danny dies on purpose as well as deliberately sabotaging himself and Arin just to annoy him after Arin accuses him of not following his instructions. Arin sometimes does the same out of agitation toward Danny.